1. Field of the Invention
The present invention relates in general to a fluid retention assembly, and more particularly, to a fluid retention assembly having a matrix for use in association with an iontophoretic delivery device which, is configured for, among other things, ocular applications.
2. Background Art
Fluid retention assemblies having a matrix for use in association with iontophoretic delivery devices have been known in the art for several years. While conventional matrices of fluid retention assemblies have become commercially available, their use in especially sensitive applications, such as the ophthalmic administration of a medicament, or the administration a medicament to broken or otherwise damaged skin remains problematic. In particular, conventional matrices used in non-sensitive applications are fabricated from materials which can be too abrasive, contain too many particulates, and/or facilitate a undesirable degree of irritation for especially sensitive applications. For example, conventional matrices may scratch the surface of a patient""s eye, or may further irritate a broken or damaged surface of a patient""s body. Furthermore, conventional matrices may leave residual particulates and/or lint, which can be especially troublesome for ophthalmic applications. As such, there is a demand for a fluid retention assembly having a matrix, which is configured for sensitive iontophoretic applications, including ocular iontophoretic applications.
The present invention is directed to a fluid retention assembly for use in association with an iontophoretic drug delivery device comprising: (a) a matrix, wherein the matrix is fabricated from a hydroxylated polyvinyl acetal; (b) a first excipient associated with the matrix, wherein the first excipient comprises a substantially non-ionic thickening agent; and (c) a second excipient associated with the matrix, wherein the second excipient comprises a hydration enhancer.
In a preferred embodiment of the present invention, the first excipient comprises a cellulose ether, such as a hydroxypropylcellulose.
In another preferred embodiment of the present invention, the second excipient comprises an oxyalkylene polymer, such as a polyethylene glycol. Preferably, the polyethylene glycol has an average molecular weight ranging from approximately 1,000 to approximately 9,000.
In yet another preferred embodiment of the present invention, the matrix further comprises a therapeutic amount of a medicament, such as, but not limited to, a VEGF-inhibiting aptamer, an alpha-interferon, a beta-interferon, a gamma-interferon, dexamethasone sodium phosphate, lidocaine hydrochloride, amikacin, and/or gangcyclovir.
The present invention is also directed to an ocular iontophoretic drug delivery device comprising: (a) a fluid retention assembly comprising: (1) a matrix, wherein the matrix is fabricated from a hydroxylated polyvinyl acetal; (2) a first excipient associated with the matrix, wherein the first excipient comprises a substantially non-ionic thickening agent; and (3) a second excipient associated with the matrix, wherein the second excipient comprises a hydration enhancer; (b) an active electrode assembly associated with the fluid retention assembly; (c) a counter electrode assembly, wherein the counter electrode assembly is configured for completing an electrical circuit between the active electrode assembly and an energy source; and (d) an energy source for generating an electrical potential difference.
The present invention is further directed to a method for preparing a fluid retention assembly for use in association with an iontophoretic drug delivery device comprising the steps of: (a) providing a first excipient, wherein the first excipient comprises a substantially non-ionic thickening agent; (b) providing a second excipient, wherein the second excipient comprises a hydration enhancer; (c) preparing a solution of the first and second excipients in a solvent; (d) impregnating a matrix fabricated from a hydroxylated polyvinyl acetal with the prepared solution; and (e) drying the matrix.
In a preferred embodiment of the invention, the method further comprises the steps of associating a medicament with the matrix, such as a VEGF-inhibiting aptamer, an alpha-interferon, a beta-interferon, a gamma-interferon, dexamethasone sodium phosphate, lidocaine hydrochloride, amikacin, gangcyclovir, and/or mixtures thereof.
In another preferred embodiment of the present invention, the step of drying the matrix includes the steps of: (a) air drying the matrix at ambient temperature for approximately 15 hours; and (b) heating the matrix in an oven to approximately 50 degrees centigrade for approximately 2 hours after the step of air drying the same.
In yet another preferred embodiment of the present invention, the method further comprises the step of freezing the matrix after the step of drying the same.